close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2118180

код для вставки
May 24, 1938.
r
H. G. FERGUSON
2,118,18‘0
TRACTOR FOR AGRICULTURAL IMPLEMENTS
Filed Jan. 27,v 1937
'
2 Sheets-Sheet l
May 24, 1938-
H. G1 FERGUSON
2,113,180
TRACTOR FOR AGRICULTURAL IMPLEMENTS
Filed Jan. 27, 1937
.
u
,95
2 Sheets-Sheet 2
'II
‘2,118,180.
Patented May 24, 1938
' UNITED STATES PATEN
2,118,180
TRACTOR ron AGRICULTURAL IMPLE
MENTS
Henry George Ferguson, Belfast, Northern
Ireland
v
'
>
'
'
'
Application January 27, 1937, Serial No. 122,609
In Great Britain February 5, 1936
/
20 Claims. (CI. 97-50)
This invention relates to improvements in con
control lever worked by the operator. If the
troi' of tractor-drawn agricultural implements, operator unduly forces the control lever the safety
means,‘ for example, a shock-absorbing spring
and more especially to tractors having a pres
will prevent any excessive load being imposed
sure ?uid power-operated control unit for auto
5 matically controlling the depth of the implement
and/or for raising and lowering of the implement
in a manner similar to the power unit described
in my prior patent speci?cation No. 1,687,719.
It has been found that when an implement is
1 O attached to a tractor as a unit and controlled
for depth regulation by ?uid pressure means, the
operating ?uid tends to become overheated and
aerated if it has to be pumped continuously and
controlled under pressure.
To overcome this di?iculty an object of the in
vention is to provide that the ?uid is controlled
on the suction side of the pump and so that the
supply can be varied, cut off or discharged in
accordance with requirements for automatically
20 keeping the implement at a regular depth and/or
also for raising and lowering the implement.
A further object is to effect the control by a
valve the length of which, and the distance be
tween the suction port or ports and the release‘
N OI port or ports, are so arranged as to providethat
both suction and release ports may be covered
at the same time, whereby movement of the ?uid
can be prevented in either direction. The pe
riod when the valve covers both ports is what I
30 term the “dead point” or mid-position.
When the implement is operated in the ground
at a predetermined depth which has been ?xed
by manual control means, the valve remains on
the “dead point” until changed froni it by a varia
35 _ tion in the draft.
For example, if the implement
were to go deeper the draft would be increased.
This would open the suction ports and allow ?uid
into the pump. The implement would then be
upon the mechanism or the valve.
An implement such as hereinbefore referred'to
is usually transported‘ on the tractor by raising
it to a predetermined height above‘the ground.
A further object is to provide automaticmeans
connected with the mechanism for cutting off the 10
?uid supply to the pump, so that when the imple
ment reaches the predetermined height it will
automatically stop ascending. This may be done,
for example, by arranging that when a ram
piston, which operates the raising mechanism, 15
reaches a predetermined position it will come into
engagement with control mechanism for the
?uid valve and the valve will be moved to the
“dead point” where the fluid supply is cut off.
In a preferred arrangement oil is drawn from 20
a tank or sump by a suitable form of pump and
in the pipe line leading to the suction side of
the pump, I provide a piston valve, in a suitable
valve chamber, for controlling the oil, the move-_
ments of the said piston valve being controlledby
a. hand lever convenient to the operator on"
'‘
a
tractor, and also automatically controlled,
lever, whenofrequired,
variations
draft on working
the implement,v
independently
the
._
the automatic control and also, when required, 30
serving to regulate the automatic control of the
implement. On the pressure or ramside of the
pump I provide a port or passage connecting
with the aforesaid valve chamber so that when
the valve is moved, either by hand or automati 35
cally, to a predetermined position, this port will
be uncovered and allow the ?uid to ?ow back
again to the sump or tank. When the pump is
automatically raiscdto the predetermined depth ~ in operation and the ?uid has passed the pump, it
40 and the valve would then automatically return to
the “dead point”. Similarly, if the draft on the
implement were reduced due to its becoming
is led to a ram chamber to operate the ram by 40
means of which the implement is operated, or
controlled. Thus continual pumping and conse
, shallower in the ground, the mechanism would ;. quent overheating and aeration of the oil is avoid
work in the opposite way by the uncovering of
the release ports and allowing the implement to
return to the predetermined depth, the valve
again being automatically moved to the dead
point. Thus automatic control is effected with
out continuously pumping ?uid under pressure, so
that overheating and aerating are avoided.
It has been found that in operation some imple
ments are inclined to move the ?uid control valve‘
more than necessary. A further object is to pro
vide damping means on the valve so as to slow or
55 reduce these movements, and so save excessive
wear on the valve and its controlling mechanism
and on the pump.
ed owing to the control being on the suction
side of the pump.
45
The invention will now be described vby way of
example only with reference to a speci?c embodi
ment thereof as shown on the accompanying
drawings wherein:Fig. 1 is a part longitudinal sectional elevation 50
of the rear portion of a tractor having means
provided for hydraulic control of an implement
attached to the tractor, the implement being
shown in the raised position.
Fig. 2 is a view partly in section looking in the 55
direction of the arrow K, Fig. 1 with the rear
axle and crown ‘gear housing removed.
Fig. 3 is a view looking in the direction of the
To prevent damage to the mechanism for op
erating the control valve, a further object is to arrow Y, Fig. 1 with the tractor casing removed
>
60 provide safety means between the valve and the \ at the joint Z.
Fig. 4 is a sectional detail elevation of the hy
draulic pump and control valve.
Fig. 5 is a front elevation, one half in section,
of the hydraulic pump and showing the control
valve and connection thereto;
Fig. 6 is a sectional view to- a larger scale, on
the line VI-VI, Fig. 4. ‘
Fig. 7 is a sectional view, to a larger scale, on
the line VII-VII, Fig. 4.
Fig. 8 is part sectional plan of the ram cylinder
10
" showing the arrangement of the safety valve.
Referring to the drawings:
\ In the example shown in the drawings, I de
rying a crank it, theiother end of which is pivot
ally connected to the top end of a lever H. The
lower end ll‘ of the lever I1 is connected with
a rod or wire II which, in turn, is connected at
its opposite end to a spring loaded lever l9, piv
oted at i9‘, and forked at its end i9h to engage
the head of the valve l4. Movement of the hand
lever, l5 in the direction of the arrow shown in
Fig. 1 will move the end I‘!- of the lever i1 around
a fulcrum 20, the lever being kept in contact with
the fulcrum 20 by the spring i4‘ (Fig. 4) which is
provided on one end of the valve i4; such move
ment of the‘hand lever causing the valve i4 to
move inv the direction‘ of the arrow in Fig. 4.
notes the rear portion of the tractor casing, 2
the rear wheels of the tractor, 3 the rear axle of
The spring l4“ also serves to keep looseness out 15
the tractor, 4 denotes theimplement and 5 and
of the mechanism and serves to take up any wear
5 respectively denote the upper and lower link
that may arise. Movement ofv the hand lever ii
connection between the tractor and the imple
ment, which, in this particular example, is a
in the opposite direction will reverse the move
cultivator. ' Obviously this may be replaced by
any other implement as the occasion demands.
On the tractor and located in front of the rear
ment ofthe valve.
‘
,
The implement 4, as previously stated, is piv 20
otally connected to the upper and lower links 5
axle as. shown in Fig. 1, is a hydraulic ram ‘I,
and 5 by means of its frame 4'. The upper link
5 is connected at its end 5‘ with a rocker 24 piv
which includes the cylinder 1° and the piston of
which is pivotally connected to the connecting
rod 1' which, in turn, is pivotally connected at ‘lb
rocker 24 is' pivotally connected to a rod 25 on 25
oted at 24" to the back of the tractor. The
which is mounted a heavy compression spring 29.
to the arm 5' mounted on the ram shaft 8. Con r The rod 25 is pivotally connected at its oppo
nected to the shaft 5 are two lift arms 9 which, site end to a lever 26 which is pivoted at ‘its up
in turn, are connected by two lift rods iii to the
30 lower links 5 connecting the frame 4' of the
implement 4 with the tractor, the implement 4
being shown in the raised position. Oil is drawn
from a tanker sump Ii by a pump I 2 which, to
gether with the ram connected to it by the pipe
35 22, constitutes a pressure-?uid control unit or
assembly referred to in the claims as a “unit"
for convenience, the pump being continuously
driven by the tractor engine while the engine is
running. Details of this pump are shown at
Figs. 4 and 5. It is a four-cylinder unit with
two pairs of horizontally-opposed cylinders 31.
Each pair of~pistons 35 projects from the two
ends of a square frame 35 embracing a sliding
block 45, the reciprocating motion for the blocks
45 being obtained from eccentrics 4| mounted on
perend 25' to the tractor casing and at its lower
end to a rod 21 on which is fastened the fulcrum 30
20, previously referred to. Beyond the fulcrum
20 the front end of the said rod is slidably sup
ported in a bearing 28. The rod 21 passes
through a slot in the lever l1.
As regards the manual control of the imple
ment the arrangement is as follows:—
When the hand lever i5 is. moved from the
vertical position in the direction of the arrow in
Fig. 1 the lever I1 is moved anti-clockwise about
the fulcrum 20, moving the rod or wire ii to the .
right, which in turn operates the articulated le
ver i9 thereby moving the valve i4 to the left
(Fig. 4) and uncovering the release ports 23 and
allowing the oil to escape from the ram cylinder
‘I3 at a slow rate. The piston thus moves slowly
into the cylinder ~ 1° under the weight of the
the driving shaft 42. The two eccentrics 4i are
set at right angles as‘ can be seen from Fig. 4, implement, which drops gently to the ground
so that the four pistons 35 operate successively and, as a result of the draft which is then im
giving a su?lciently regular ?ow to the oil to pre
posed on the implement, it tends to turn in an
vent any perceptible irregularity in the lift of anti-clockwise direction about the pivotal con
50 the tool frame. The delivery valves 33 are
nection of the frame 4“. This tendency is re
mounted vertically above the suction valves 43, as sisted ‘by the spring 29 which is compressed by
shown to the left in Fig. 5. From the chambers ' the rod 25 moving to the left,,swinging the lever
44 above the delivery valves 33, the oil is taken 25 and causing the rod 21 with the fulcrum 20
through sloping branch passages 45 to the un
thereon to swing to the left by its connection to
derside of the ball valve 34, shown below the de
the link it. This return movement of the lever
livery outlet 46 in Fig. 4, to which outlet the pipe .i ll allows the valve l4 to move to the right and
22 is connected. When the pump is in operation, to cover the release ports 23 without moving the
the ball valve is lifted, and the oil has two pos
hand lever l5 from the position to which it was
sible paths, one being through the delivery out
moved by hand. When the implement reaches
let 45 to the pipe .22 and the ram cylinder 1°, the desired depth the valve l4 covers the ports 2|
and the other through the by-pass passage 35 to and 23, and it will be seen that the depth is reg
a circular space 35 embracing the sleeve of the
piston control valve l4. This sleeve is drilled ulated by the‘position of the lever l5.
Adjustment of the hand lever II from the po
as at 23 to give a restricted release port opening
into the sleeve centre space, the restriction limit
ing the speed of lowering the implement as later
described. The piston valve I4 is provided in the
passage. i3 which leads to the suction side of the
70 pump.v This valve I4 is for controlling the ad'-‘
mission of oil, its movements being controlled by
a hand lever i5, (Fig. 1). convenient to the op
erator, on the tractor. The hand lever i5 is con
nected with the piston valve l4 as follows:—
Its lower end l5Il is mounted on a shaft car
s‘ition shown in Fig. 1 (the raised position) moves 65
the top of lever I1 to the left and the imple
ment is lowered as above described. This low
ering movement continues until the fulcrum 25
has been moved su?lciently far to the left to al
70
low the valve i4 to close the ports 23 and arrest
the lowering movement of the implement. Thus
the further the lever i1 is moved to the left by_
the hand lever IS, the vfurther will the imple
ment be lowered before there has been sumcient 75
3
2,118,180
movement of the fulcrum to arrest the lower
to flow back from the ram cylinder 1c andwill 7
ing movement.
allow the implement to fall back to the predeter
mined depth of cut. When the predetermined
depth has been reached the control valve M will
To raise the implement, the hand lever | 5 is
moved back to the vertical ‘position, the bottom
end of the lever |‘| being moved to the left, there
by moving the rod or wire i8 and lever l9 so
that the valve I4 is moved to the right and un
covers the ports 2|, which are the inlet ports of
the pump, allowing oil to flow to the pump which,
operating through the ram and linkage 8“, 8, 9,
l0 and 6, raises the implement. As‘ the imple
ment rises, the rod 25 (due to the removal of the
draft on the implement) is moved by the spring
29 to the right, thereby swinging the lower end
15 of the lever 26 to the right which in turn moves
the rod 21 and fulcrum 20 thereon, to the right,
bringing the lever IT to the right therewith,
which, operating through the rod or wire l8 and
lever l9 moves the valve to the left, so that, when
20 the implement is fully raised, the valve ll covers
the ports 2| and 23, cutting oi the supply of oil
to the pump and cutting off the escape of oil
fromthe pump and keeping the implement in
the raised position.
25
I will now describe the action of the automatic
control:-—Firstly, the control lever | 5 is set to
give the desired predetermined depth of cut in
the ground. As long as the implement is work
ing, and the draft on the implement remains the
again come back to the dead point under the ac
tion of the increased draft as previously de
scribed.
It will be noted that control of the oil to the
pump | 2, which supplies the oil under pressure
to the ram cylinder‘, is arranged on the suction 10
side of the pump.v The pump is operating con
tinuously while the tractor is in motion but ?uid
is only admitted to the suction side of the pump
when conditions require that the implement is
to be raised on the tractor.
It will thus be seen 15
that the pump is only in effective operation when
oil is actually required to be pumped to the ram
cylinder and thus continuous pumping of the oil
is avoided, and also any excessive heating and
aeration of the oil. When the implement is op-v 20
eratedin the ground at a predetermined depth,
which has been ?xed by the control lever, the
valve remains on the dead point until changed
from it by variation in the draft or by the operator
when he wishes to raise the implement on the 25
tractor.
‘
.
Under some conditions of operation and in op
erating some implements there may be an in
clination to move the oil control valve more than
30 same, the compression load on the spring 29 will ‘ necessary and thus cause unnecessary pumping 30
be constant, it being understood that, in opera
of the oil. To avoid this, I provide damping
tion, the links 5 and 6 are respectively in com
means in connection with the control valve. For
pression and tension. Under these conditions example, I provide, as shown at Fig. 4 a cylinder
the valve ll will remain on the “dead point”, or dash-pot in which the end Nb of the valve l4
35 that is, with the ports 2| and 23 closed. This po
acts as a piston, and by providing a very small 35
sition of the valve I4 is shown at Fig. 4, no move
aperture 30“ at the end of the cylinder 30 and
ment of the oil taking place in either direction
trapping oil in the cylinder 30, the piston end
and consequently no movement of the ram tak
Mb will by its movement, either draw oil into, or
force oil out of, the cylinder 30 through the small
ing place in either direction.
If, however, the implement l is subjected to
40
an increase in draft due, for example, to the front
wheels of the tractor rising on a height and pitch-_
ing the implement more deeply into the ground,
such increase will instantaneously be transmit
ted to the rod 25 causing an increase in the com
pression thereon, which in turn, will cause the
rod to compress the spring 29 further. At the
same time the lever 26 will be moved about its
pivot 26“ with a resultant movement of the rod
21 and the fulcrum 20 thereby permitting the
lever I‘! to move to the left in Fig. 1, that is,
forwardly under the action of the spring H“
on the valve II. This forward movement of the
lever l1, through the rod l8 will cause a corre
55 sponding movement of the spring loaded lever l9
which will allow the spring “a to move the valve
l4 rearwardly thus uncovering the suction ports 2|
so that oil will be admitted to the pump l2 which
then pumps the oil to the ram cylinder 1° which
60 will be moved outwardly and will raise the im
plement in the manner already described.
When the implement has been raised to a point
- where the draft thereon again reaches the pre
determined amount, to give the necessary depth
of cut, the spring 29 reacts and brings the valve
l4 back again to the dead point with both the
ports 2| and 23 closed.
If the implement be subjected to a reduction
in draft, due for example, to the front wheels,.of
the traction dropping into a hollow and so raising
the implement relatively to the ground and thus
making it cut too shallow, the action upon the
spring 29 will be reversed and the valve M will
be moved in a forward direction.
This will open
hole 3|!a with the result that a damping ac
40
tion is given to the valve.
To prevent damage to the mechanism for oper
ating the control valve I may make the lever l9
in two portions |9°, l9d, hinged together as
shown in the detail at Figs. 5 and 5“. This lever 45
is of course situated between the valve l4 and
the control rod IT, a spring 3| serving normally
to hold together the two portions of the lever l9
as shown in Fig. 5". The arrangement is such
that if ,the operator unduly forces the control,
the jointed lever l9, which can only transmit a
certain load (depending on the strength of the
spring 3L) will, when its load is exceeded, per
mit of the control lever l5 being moved to the
full extent of its travel without damaging the 55
control valve or its mechanism, the excess move
ment or force applied simply causing the por
tion l9a to pivot and stretch the spring 3|.
An implement such as hereinbefore described
is usually transported on a tractor by raising
it to a predetermined height above the ground.
I provide automatic means connected with the
mechanism hereinbefore described for cutting
oil’ the supply of ?uid to the pump l2 so that
when the implement has been raised to a prede
termined height it will automatically stop ascend
ing. In the example shown this is accomplished
in the following manner:—
'
When the implement 4 is raised by the mecha
nism hereinbefore described and shown in the 70
drawings, the ram piston, in moving rearwardly,
that is, outwardly, contacts with a projection |'lb
on the lever I‘! (Fig. 2) and in continuing its
movement it moves the lever |'| rearwardly, giv
75 the restricted release ports 23, will allow oil/ ing a corresponding movement to the valve con
75
4
_
2,118,180
trol rod l8 and lever l9 and so moving the valve
H to cause it to come to the dead point and
close off the supply of oil to the pump. Thus
when the implement is being transported no ?uid
of such length that when it is in its mid-position
or "dead point” it covers both said ports; and
control means for moving said valve to one or
other side to raise or lower the implement.
7. For a tractor foragricultural implements.
a pump for supplying a pressure ?uid for con
is being pumped, which again provides the de
sired result that the oil’ is not being continuously
moved by the pump and thereby avoiding heat
ing and aerating as previously mentioned.
A safety valve may if desired be provided some
10 where on the pipe line 22 between the pump and
trolling the height of the implement with refer
ence to the tractor, comprising means for driv
ing the pump from the tractor-propelling means
the ram cylinder 1" or on the ram cylinder
for controlling the admission of ?uid to the
pump and thus the operative effect of the pump
itself, the spring loaded valve 32 shown in Figs.
. 1 and 8 on the ram cylinder 1° serves to protect
the system from excessive pressures, the valve be
15 ing opened by the end of the rod 21 abutting
against it, as for example, when the implement
strikes an obstruction.
I claim:—
L '
.
'
and valve means on the inlet side of the pump 10
on the implement.
8. In a tractor having means for the attach
ment of an agricultural implement and having 15
a pressure-?uid control unit, including a pump,
for raising and lowering the implement with
reference to the tractor; valve means on the suc
1. A tractor having means for the attachment
of an agricultural implement and a pressure-?uid
control unit, including a pump, for raising and
tion side of said pump whereby operation of
the unit is controlled by controlling the admission 20
of operating ?uid to the pump, manual control
lowering the implement with reference to the
means for said valve means, and means for damp
tractorand valve means on the suction side of
said pump whereby the operation of the unit is
ing the movement of said valve means.
9. In a pressure-?uid control unit for raising
25 eilected by controlling the admission of operat
ing ?uid to the pump.
2. A tractor having means for the attachment
of an agricultural implement and having a pres
sure-?uid control unit, including a pump, for
30 raising and lowering the implement with refer
and lowering an agricultural implement with 25
reference to a tractor and which includes a pump;
valve means for the pump comprising a piston
valve, an inlet or suction port and an outlet
port spaced from the inlet port, the valve being
of such length that when it is in its mid-position 30
ence to the tractor, valve means on the suction
side of said pump whereby operation of the unit
or “dead point" it covers both said ports, and
a dash pot for damping the movement of the
is effected by controlling the admission of operat
piston valve.
ing ?uid to the pump and manual control means
35 for said valve means.
3. A tractor having means for the attachment
of an agricultural implement and having a pres
sure-?uid control unit, including a pump, for
raising and lowering the implement with refer
40 ence to the tractor, valve means on the suction
side of said pump whereby operation of the
unit is effected by controlling the admission of
operating ?uid to the pump, manual control
‘
10. In a tractor having means for the attach
ment of an agricultural implement and a pres 35
sure-?uid control unit, including a pump, for
raising and lowering the implement with refer
ence to the tractor; valve means on the suction
side of said pump whereby the position of the
implement is controlled by controlling the admis 40
sion of operating fluid to the pump and pressure- ~
operable safety valve means on the delivery side
of said pump.
'
sure-?uid control unit, including a pump for
11. A tractor adapted for the attachment of an
agricultural implement and having a pressure 45
?uid control unit, including a pump, for raising
and lowering the implement with reference to
the tractor, valve means on the suction side‘ of
said pump whereby operation of the unit is ef
raising and lowering the implement with refer
fected by controlling the admission of operating 50
means for said valve means, and means for
automatically controlling said valve means in ac
cordance with the draft on the implement.
4. A tractor having means for the attachment
of an agricultural implement and having a pres
ence to the tractor, valve means on the suction
side of said pump whereby operation of the unit
is effected by controlling the admission of oper
ating ?uid to the pump and means for automati
cally controlling said valve means in accordance
with the draft on the implement.
5. A tractor comprising means for the attach
ment of an agricultural implement and a pres
sure-?uid control unit for raising and lowering
60 the implement with reference to the tractor, said
unit comprising a ?uid pump, a pressure-?uid
operable device connected to the pump, means
for driving the pump from the tractor-propelling
means, valve means on the suction side of the
pump for controlling the admission of ?uid to
the pump, manual control means for the valve
means and means for automatically controlling
said valve means in accordance with the draft
on the implement.
6. In a pressure-?uid control unit for rais
ing and lowering an agricultural implement with
reference to a tractor and which includes a
pump; valve means for the pump‘comprising a
- piston valve, an inlet or suction port and an
outlet port spaced therefrom, the valve being
?uid to the pump, manual control means for said
valve means, and a lost motion, safety means in
said manual control means.
12. In a tractor having means for the attach
ment of an agricultural implement and a pres 55
sure-?uid control unit, including a pump, for
raising and lowering the implement with refer
ence to the tractor; valve means on the suction
side of said pump whereby the implement-con
trolling eifect of the unit is controlled by con
trolling the admission of operating ?uid to the
pump, and means for cutting oil the supply of
?uid to the pump when the implement has been
raised to a predetermined height.
13. In a tractor having means for the attach
ment of an agricultural implement and having
a pressure-?uid control unit, including a pump,
for raising and lowering the implement with
reference to the tractor; valve means at'the suc
tion side of said pump whereby operation of the 70
unit is effected by controlling the admission of
operating ?uid to the pump, manual control
means for said valve means, means for damping
the movement of said valve means and a pres 75
5
2,118,180
sure-operable safety valve on the delivery side
of said' pump.
14. A tractor adapted for the attachment of
an agricultural implement and having a pres
points to the manual control and to the valve,
a fulcrum movable in accordance with the draft
on the implement against the action of said re
sistant means and-adapted to co-operate with
sure-?uid control unit, including a pump, for
raising and lowering the implement with refer
said lever, the arrangement being that when the 5
point of the lever operatively connected to the
ence to the tractor, valve means on the suction
side of said pump whereby the position of the
implement is controlled by controlling the admis
10 sion of operating ?uid to the pump, a manual‘
and automatic control for said valve means, a
lost motion safety means in said control and a
pressure-operable safety valve means on the de
livery side of said pump.
valve is moved to shift the valve from its mid
position, the resultant movement of the imple
ment by said device causes a variation in draft
which moves the fulcrum in such direction that 10
said point of the lever is returned to the posi
tion corresponding to the mid-position of the
valve which again closes the admission and re
15. In a tractor having means for the attach
ment of an agricultural implement and a pres
sure-?uid control unit, including a pump, for
raising and lowering the implement with refer
ence to the tractor; valve means at the suction
20 side of said pump whereby the operation of the
unit is effected by controlling the admission of
operating ?uid to the pump, pressure-operable
safety valve means on the delivery side of said
pump and means for cutting off the supply of
25 ?uid to the pump when the implement has been
raised to a predetermined height.
16. A tractor having means for the attach
ment of an agricultural implement and having
a pressure-?uid control unit, includinga pump,
30
for raising and lowering the implement with
reference to the tractor, valve means on the suc
lease ports.
‘
19. A tractor having means for the attach 15
ment of an agricultural implement, a pressure
?uid control unit for raising or lowering the im
plement with reference to the tractor and com
prising an oil pump, means for driving same from
the tractor-propelling means, a ram device hav 20
ing a ?uid connection with the pump and a
mechanical connection with the implement, a
piston valve co-operating with admission and
release ports for the pump and of such length
that in its mid-position it covers said ports, a 25
manual control for said valve including a lever
consisting of two pivotally connected parts nor
mally retained in a predetermined angular posi
tion by spring means and an automatic control -
for the valve operated against the action of re 30
sistant means by the draft on the implement, a
tion side of said pump whereby operation of the
“?oating lever” operatively connected at spaced
unit is eifected by controlling the admission of
points to the manual control and to the valve, a
fulcrum movable in accordance with the draft
on the implement against the action of said re 35
sistant means and adapted to co-operate with
operating ?uid to the pump, a manual and
35 automatic control for said valve means, a lost
motion, safety means in said control, pressure
operable safety valve means on the delivery side
of said pump and means for cutting on‘ the sup
ply of ?uid to the pump when the implement
40 has been raised to a predetermined height.
17. A tractor having means for the attach
ment of an agricultural implement, a pressure
?uid control unit for raising or lowering the im
plement with reference to the tractor and com
45 prising a ?uid pump, means for driving same
from the‘ tractor-propelling means, a pressure
operable device having a ?uid connection with -
said lever, the arrangement being that when the
point of the lever operatively connected to the
valve is moved to shift the valve from its mid
position, the resultant movement of the imple 40
ment by said device causes» a ‘variation in draft
which moves the fulcrum in such direction that
said point of the lever is returned to the position Y
corresponding to the mid-position of the valve
which again closes the admission and release 45
ports.
'
20. A tractor having an agricultural imple
the pump and a mechanical connection with the
ment pivotally attached by links and comprising
implement, a piston valve co-operating with ad
spring means for resisting movement of the im
plement due to the draft thereon and a fulcrum
50 mission and release ports for the pump and of
such length that in its mid-position it covers
said ports, a manual control for said valve and
an automatic control therefor including a mem
ber operated by the draft on the implement act
55 ing against resistant means, the valve being re
turned to its mid-position when said pressure
operable device is set in operation due to dis
placement of the valve to one or other side of
said mid-position.
'
18. A tractor having means for the attach
ment ‘of an agricultural implement, a pressure
?uid control unit for raising or lowering the im
plement with reference to the tractor and com‘
prising an oil pump, means for driving same from
65 the tractor-propelling means, a ram device hav
ing a ?uid connection with the pump and a
mechanical connection with the implement, a
60
piston valve oo-operating with admission and
release
for the pump and of such length
that
in
its
mid-position
it covers said ports, a
70
manual control for said valve and an automatic
control therefor operated against the action of
resistant means by the draft on the implement,
a "?oating lever” operatively connected at spaced
movable in accordance with the displacement of ~
said spring and comprising an oil pressure power
unit including a pump driven by the tractor pro
pelling means, a piston and cylinder device hy
draulically connected to said pump and mechani 55
cally connected to said links, a pressure operable
safety valve connected to the discharge side of
the pump and a piston valve at the admission side
of the pump adapted, in its mid-position to cover
pump admission and release ports and control 60.
means for said valve comprising a manually oper
able handle connected to one/end of a “?oating
lever” connected at its other end to the piston
valve through a lever consisting of two pivotally
connected parts retained in a predetermined
angular position by spring means, said movable
fulcrum being adapted to co-operate with said
“?oating lever” so that operation of the piston
device has for effect to return the piston valve '
to its mid-position, and said piston having abut
ment means adapted to return the piston valve 70'
to its mid-position when the implement has been a
raised to a predetermined height on the tractor.
HENRY GEORGE FERGUSON.
Документ
Категория
Без категории
Просмотров
0
Размер файла
960 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа